CN103472176B - Detect the method for DMF residual quantity in PU leather - Google Patents
Detect the method for DMF residual quantity in PU leather Download PDFInfo
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Abstract
The present invention relates to a kind of method detecting DMF residual quantity in leather.Described method comprises the steps: step 1: use the DMF in ionic liquid leaching PU leather, obtain ionic liquid extract liquid, and wherein said ionic liquid is at room temperature liquid ionic liquid; And step 2: adopt headspace gas chromatography-mass spectrometric hyphenated technique, the DMF in the ionic liquid extract liquid obtain step 1 detects, thus conversion obtains the content of DMF in PU leather.The present invention selects under room temperature as this novel, green solvent of liquid ionic liquid is extraction agent, extract the DMF in PU leather, and headspace gas chromatography-MS can directly be used for analyzing DMF content in extract, therefore, detection method provided by the invention, environmental friendliness, simple to operate, favorable reproducibility, the recovery is high, and accuracy is high.
Description
Technical field
The present invention relates to N in a kind of detection leather, dinethylformamide (N, N-dimethylformamide, DMF) method of residual quantity, more specifically, relate to and a kind ofly use ionic liquid as extraction agent to extract DMF residual in PU leather, then carried out the method detected by headspace gas chromatography-mass spectrometry.
Background technology
PU is the abbreviation of English ployurethane, Chinese polyurethane, PU synthetic leather and Synthetic Leather, in a large number for automobile and room interior trim.But DMF is widely used as resin slurry solvent in the production run of PU synthetic leather.Although substantially removed DMF solvent by desolventizing, washing, drying and other steps in subsequent production, but in the middle of rete, still there is DMF to remain, these residual DMF are slowly evaporated by high molecular space, not only on environment but also the health affecting the mankind.In sum, developing DMF detection method fast and accurately in a kind of PU synthetic leather, is very necessary with DMF content in control PU synthetic leather exactly.
Bibliographical information distilled water extracts the DMF in PU leather, then uses the DMF in methenyl choloride strip aqueous, the chloroform soln after extraction is carried out gas chromatographymass spectrum detection, thus determines the content of DMF in leather.Because DMF is all infinitely miscible in water and methenyl choloride, therefore strip as document reported, a large amount of methenyl choloride need be used through repeatedly stripping.The solvent toxicity that the method uses is large, repeatedly to strip complex operation, and the recovery is not high, reappearance poor (Ma Hewei .GC-MS measures the residual quantity [J] of dimethyl formamide in leather. Chinese leather, 2009,38 (23): 38-41).
DMF is a kind of aprotic polar solvent, can be miscible with multi-solvents, so the selection of Extraction solvent directly affects testing result.Select DMF residual in Solvent Extract methods PU leather, can produce PU leather when extracting DMF in PU leather and dissolve, the equitant peak with DMF may be occurred by the material that is dissolved down when instrumental analysis in such PU leather, affect the detection of DMF, cause error to analysis; And select inorganic solvent water to be extraction agent, because water is inapplicable in many instrumental analysis, cannot directly detect after extraction, need as above-mentioned document reported through methenyl choloride reextraction after detect.Thus, the selection of Extraction solvent has material impact to the detection of DMF in PU leather.For this reason, need to select a kind of suitable Extraction solvent with the method for DMF residual quantity in developing the high detection PU of a kind of easy, environmental protection accuracy simultaneously and removing from office.
Summary of the invention
Technical matters
Therefore, the detection method of DMF residual quantity in the object of the present invention is to provide a kind of simple to operate, that favorable reproducibility, the recovery are high and accuracy is good PU of environmental protection to remove from office.
Technical scheme
The present inventor selects at room temperature for liquid ionic compound extracts residual DMF in PU leather, and gained extract is directly detected by headspace gas chromatography-mass spectrometry, thus completes the present invention.The method is simple to operate, favorable reproducibility, and the recovery is high, and Extraction solvent ionic liquid can be recycled.
According to the present invention, during detection PU provided by the invention removes from office, the method for DMF residual quantity comprises the steps:
Step 1: use the DMF in ionic liquid leaching PU leather, obtain ionic liquid extract liquid, wherein said ionic liquid is at room temperature liquid ionic liquid; And
Step 2: adopt headspace gas chromatography-mass spectrometric hyphenated technique, the DMF in the ionic liquid extract liquid obtain step 1 detects, thus conversion obtains the content of DMF in PU leather.
Beneficial effect
The present invention selects under room temperature as this novel, green solvent of liquid ionic liquid is extraction agent, extract the DMF in PU leather, the DMF that this ionic liquid is stronger to polarity has good dissolubility, and PU leather is not reacted, do not dissolved, so can obtain the dye molecule on purer DMF extract and a small amount of PU leather.Again owing to being at room temperature that liquid ionic liquid does not have vapour pressure, headspace gas chromatography-MS can directly be used for analyzing DMF content in extract.Detection method provided by the invention is easy and simple to handle, and accuracy rate is high, is a kind of good method to the DMF determination of residual amount in PU leather.
Embodiment
Hereafter, more specifically the present invention is described.
The method of DMF residual quantity in detection PU leather provided by the invention, it comprises the steps:
Step 1: use the DMF in ionic liquid leaching PU leather, obtain ionic liquid extract liquid, wherein said ionic liquid is at room temperature liquid; And
Step 2: adopt headspace gas chromatography-mass spectrometric hyphenated technique, the DMF in the ionic liquid extract liquid obtain step 1 detects, thus conversion obtains the content of DMF in PU leather.
In described step 1, wherein:
Described ionic liquid is at room temperature liquid, and is preferably imidazole salt ionic liquid or pyridine salt ionic liquid; Be more preferably and be selected from the ionic liquid shown in following structural formula:
i.e. N-ethyl-N-methyl tetrafluoroborate,
i.e. N-normal-butyl-N-methyl imidazolium tetrafluoroborate,
i.e. N-normal-butyl-N-methylimidazolium hydrogen sulphate salt,
i.e. N-ethylpyridine tetrafluoroborate,
i.e. N-normal-butyl pyridinium tetrafluoroborate salt, and
i.e. N-normal-butyl pyridine hydrosulfate; And most preferably be N-normal-butyl-N-methyl imidazolium tetrafluoroborate.
Using the N in ionic liquid leaching PU leather, during dinethylformamide, undertaken by following operation: accurately take PU and remove from office sample, be cut into suitable size, then add described ionic liquid to extract, obtain ionic liquid extract liquid, wherein every 1 gram of PU removes from office the ionic liquid that sample adds 10ml ~ 20ml.More specifically, take 5gPU and remove from office sample, be accurate to 0.01g, shred, be placed in 100ml band plug conical flask, in conical flask, add the ionic liquid of 50 ~ 70ml as Extraction solvent, and cap sealing; Then be fixed in ultrasonic extraction apparatus by this conical flask, at 50 ~ 75 DEG C, ultrasonic extraction 1 ~ 2h, through filtering after extraction terminates, obtains ionic liquid extract liquid.
In described step 2, adopt external standard method headspace gas chromatography-mass spectrometric hyphenated technique, the DMF in the ionic liquid extract liquid obtain step 1 detects, thus conversion obtains the content of DMF in PU leather.
More specifically, first, draw the standard working curve of DMF: according to the method for the use ionic liquid leaching PU leather described in step 1, use ionic liquid leaching not containing the PU leather of the same race of DMF, gained ionic liquid leaching liquid is as blank solution; The DMF standard working solution of 5 variable concentrations is prepared with this blank solution, headspace gas chromatography-GC-MS is used to detect this DMF standard working solution, the peak area of the DMF obtained and corresponding DMF concentration are carried out regretional analysis, calculates standard working curve and the equation of linear regression thereof of DMF;
Then, ionic liquid extract liquid above-mentioned steps 1 obtained is as solution to be measured, under the experiment condition identical with detecting DMF standard working solution, headspace gas chromatography-GC-MS is used to detect, the DMF peak area value obtained is brought in the equation of linear regression of the standard working curve of above-mentioned DMF, calculate the concentration of DMF in solution to be measured, thus calculate the residual quantity of DMF in PU leather;
Wherein, the described PU leather of the same race not containing DMF is that PU leather is cut into suitable size, such as, shred into about 1mm × 1mm size, then vapor away completely to DMF 50 DEG C of vacuum drying in vacuum drying chamber, namely do not contain DMF.Usually, PU leather is 50 DEG C of vacuum drying in vacuum drying chamber, and DMF volatilizes gradually, after dry 7 days, detects, DMF do not detected by method described in EPA8270D-2007.
, describe detection method of the present invention particularly by embodiment below, but scope of the present invention is not limited in these embodiments.
Below in embodiment, the headspace gas chromatography-GC-MS used is Agilent company of U.S. 7890-5975C; DMF is pure for analyzing.
Embodiment 1
The sample adopted: clothes PU removes from office (0.5mm is thick, blue) (being provided by He Xin industry Group Plc of Zhejiang Province)
One. detect the residual quantity of DMF in clothes PU leather (0.5mm is thick, blue)
Step 1:
Take the above-mentioned PU of 5.00g and remove from office sample, shred into about 1mm × 1mm size, be placed in 100ml band plug conical flask, in conical flask, add the N-normal-butyl-N-methyl imidazolium tetrafluoroborate ionic liquid of 55ml as Extraction solvent, and cap sealing; Then be fixed in ultrasonic extraction apparatus by this conical flask, at 70 DEG C, ultrasonic extraction 1h, through filtering after extraction terminates, obtains the ionic liquid extract liquid of DMF, as sample solution to be measured.
Step 2:
(1) blank solution is prepared:
PU containing DMF removes from office the preparation of sample: shred into about 1mm × 1mm size by above-mentioned PU leather, and 50 DEG C of vacuum drying 7 days, after dry 7 days, by method detection described in this PU leather EPA8270D-2007, do not detect DMF.
The preparation of the blank solution of drawing curve: take 5.00g above-mentioned not containing the PU leather sample of DMF, be placed in 100ml band plug conical flask, add the N-normal-butyl-N-methyl imidazolium tetrafluoroborate ionic liquid of 55ml in conical flask, and cap seal; Then be fixed in ultrasonic extraction apparatus by this conical flask, at 70 DEG C, ultrasonic extraction 1h, through filtering after extraction terminates, obtains ionic liquid leaching liquid, as blank solution.
(2) DMF standard working solution preparation: the DMF standard working solution preparing 5 variable concentrations with above-mentioned blank solution, compound method is as follows:
1. precision pipettes DMF1.2ml in 10ml volumetric flask, with above-mentioned blank solution dilution constant volume, obtains the standard working solution that DMF concentration is 120ml/l.
2. the standard working solution 5ml getting above-mentioned 120ml/l is placed in 10ml volumetric flask, with above-mentioned blank solution dilution constant volume, obtains the standard working solution that DMF concentration is 60ml/l.
3. the standard working solution 5ml getting above-mentioned 60ml/l is placed in 10ml volumetric flask, with above-mentioned blank solution dilution constant volume, obtains the standard working solution that DMF concentration is 30ml/l.
4. the standard working solution 5ml getting above-mentioned 30ml/l is placed in 10ml volumetric flask, with above-mentioned blank solution dilution constant volume, obtains the standard working solution that DMF concentration is 15ml/l.
5. the standard working solution 5ml getting above-mentioned 15ml/l is placed in 10ml volumetric flask, with above-mentioned blank solution dilution constant volume, obtains the standard working solution that DMF concentration is 7.5ml/l.
(3) DMF Specification Curve of Increasing
By following headspace gas chromatography and Mass Spectrometry Conditions, the DMF standard working solution 1ml of five variable concentrations above-mentioned preparation obtained is placed in 5 ml headspace bottle respectively, headspace gas chromatography-GC-MS is adopted to detect, the peak area of the DMF obtained and corresponding DMF concentration are carried out regretional analysis, calculate standard working curve and the equation of linear regression thereof of DMF, as shown in table 1.
Headspace gas chromatography-Mass Spectrometry Conditions is as follows:
The heating-up temperature of headspace sample bottle is 120 DEG C, heating equilibration time is 45min;
A). chromatographic column: HP-5MS30m × 0.25mm × 0.5 μm
B). column temperature: 50 DEG C keep 3min, then rise to 200 DEG C with 12 DEG C/min speed, keep 4min
C). injector temperature: 200 DEG C
D). input mode: split ratio 1:20
E). carrier gas: helium, purity >=99.999%, 1.0ml/min
F). chromatography-mass spectroscopy interface temperature: 250 DEG C
G). ionization mode: EI
The peak area that table 1 standard working solution is corresponding and standard working curve equation
As shown in table 1, coefficient R 2 is 0.9992, illustrates that the linear of this analysis method can meet the demands.
(4) the DMF content in the sample solution to be measured adopting external standard method headspace gas chromatography-GC-MS detecting step 1 to obtain:
Sample step 1 obtained solution 1ml to be measured is placed in ml headspace bottle, under above-mentioned the same terms, adopt headspace gas chromatography-GC-MS to detect, the DMF peak area value obtained is brought in the equation of linear regression of the standard working curve of DMF, calculate the concentration of DMF in sample solution to be measured, thus (5mm is thick to calculate clothes PU leather, blue) in the residual quantity of DMF, be 15.00mg/kg.
Two. the accuracy of the present embodiment detection method and precision
As follows the accuracy of the detection method of the present embodiment is investigated:
Adopt and do not remove from office containing the PU of DMF, add DMF wherein, prepare three and add the mark-on sample that scalar is respectively 1.0 μ g/g, 2.0 μ g/g, 3.0 μ g/g, measure by above-mentioned sample extraction and detection method.The sample that difference adds scalar has carried out 3 mensuration, respectively according to measured quantity and the recovery and the relative standard deviation that add each Pitch-based sphere of Scalar operation.The results are shown in Table 2.
Table 2 detection method investigates result
Found out by table 2, the average recovery rate of DMF tri-mark-on levels is between 97%-100%, and standard deviation is between 3.45%-4.84%, and method detects and is limited to 10ppm, illustrates that the measurement result of this method is reliable.
Embodiment 2-13
According to the detection method that embodiment 1 is identical, the PU shown in his-and-hers watches 3 removes from office sample and carries out DMF content detection, and result is shown in Table 3.
Table 3: embodiment 2-13 experimental data
| Embodiment | PU removes from office sample | DMF content (mg/kg) |
| Embodiment 2 | Clothes-0.5mm black | 90.00 |
| Embodiment 3 | Sofa is blue with-0.5mm | 162.05 |
| Embodiment 4 | Sofa-0.5mm black | 17.75 |
| Embodiment 5 | Sofa-0.8mm black | 199.27 |
| Embodiment 6 | Case and bag are blue with-1.0mm | 33.00 |
| Embodiment 7 | Vamp is brown with-0.8mm | 496.80 |
| Embodiment 8 | Vamp is brown with-0.4mm | 15.69 |
| Embodiment 9 | Vamp-0.8mm black | 226.00 |
| Embodiment 10 | Vamp-1.0mm grey | 209.31 |
| Embodiment 11 | Decoration milky | 325.13 |
| Embodiment 12 | Sneaker vamp-1.4mm white | 1334.00 |
| Embodiment 13 | Sneaker vamp-1.4mm ash | 258.89 |
Claims (1)
1. detect a method for DMF residual quantity in PU leather, the method comprises the steps:
Step 1: use the DMF (DMF) in ionic liquid extract PU leather, obtain DMF ionic liquid solution, wherein said ionic liquid is at room temperature liquid ionic liquid, is N-normal-butyl-N-methyl imidazolium tetrafluoroborate; When using the DMF in ionic liquid extract PU leather, undertaken by following operation: take 5gPU and remove from office sample, be accurate to 0.01g, shred, be placed in 100ml band plug conical flask, the ionic liquid of 50 ~ 70ml is added as Extraction solvent in conical flask, and cap sealing; Then be fixed in ultrasonic extraction apparatus by this conical flask, at 50 ~ 75 DEG C, ultrasonic extraction 1 ~ 2h, through filtering after extraction terminates, obtains ionic liquid extract liquid; And
Step 2: adopt headspace gas chromatography-mass spectrometric hyphenated technique, the DMF in the ionic liquid extract liquid obtain step 1 detects, calculates the residual quantity of DMF in PU leather by calibration curve method.
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| CN105203681A (en) * | 2015-09-02 | 2015-12-30 | 兰州科天新材料股份有限公司 | Method for determining N,N-dimethyl formamide |
| CN107490638A (en) * | 2017-08-18 | 2017-12-19 | 天守(福建)超纤科技股份有限公司 | The residual micro DMF in the face method of inspection in a kind of analysis PU synthetic leather |
| CN108362786B (en) * | 2018-01-10 | 2022-03-08 | 杭州中一检测研究院有限公司 | Rapid solvent extraction analysis method for N, N-dimethylformamide in soil |
| CN109633004B (en) * | 2018-12-27 | 2021-08-03 | 嘉兴学院 | Method for detecting content of trichlorophenol in leather |
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Effective date of registration: 20151229 Address after: 314001 Yuexiu South Road, Zhejiang, No. 56, No. Patentee after: Jiaxing University Patentee after: ZHEJIANG HEXIN NEW MATERIAL CO., LTD. Address before: 314001 Yuexiu South Road, Zhejiang, No. 56, No. Patentee before: Jiaxing University Patentee before: Zhejiang Hexin Industry Group Co., Ltd. |